The human brain is the source of our thoughts, emotions, perceptions,
actions, and memories; it confers on us the abilities that make us
human, while simultaneously making each of us unique. Over recent years,
neuroscience has advanced to the level that we can envision a
comprehensive understanding of the brain in action, spanning molecules,
cells, circuits, systems, and behavior.

The BRAIN Initiative is a challenge and an opportunity to solve a
central mystery—how organized circuits of cells interact dynamically to
produce behavior and cognition, the essence of our mental lives. The
answers to that mystery will not come easily. But until we start, the
progress we desire will always be distant. The time to start is now.

Hoping to replicate the successes of the Human Genome Project, President Obama has thrown down the gauntlet to neurobiologists. Research into the brain is likely to yield many benefits to society. However, just as complete knowledge of the nucleotide sequence of our genomes is unlikely to offer complete understanding of our genetics, neither is comprehensive mapping of our neural circuits likely to reveal the "essence of our mental lives." A better scientific description of the brain will certainly shed valuable light on behavior. However, understanding behavior is unlikely to be as easy as characterizing neurons and neural circuits.